"There’s a lot of times in my head that I think I shouldn’t be here," he says. "I should have taken the round straight to the face. My parents would have a folded flag."

Vargas made it back home alive, thanks to two of his buddies, he says. But his battle didn't end that day nearly a decade ago. He admits there was a moment when he was so overwhelmed with the grief of losing friends to suicide and with the stress associated with school and marriage that he went looking for his gun lock.

"There was a time when I thought, screw it, I’m ready to end it," he remembers.

But the contents of his ammo box — pictures of his wife, the rounds that struck him and a list of Marines who served by his side — persuaded him to continue the fight. On Saturday, he will graduate from UC Berkeley with a degree in social work.

With his degree, Vargas plans to start a new suicide prevention program with psychologist Shauna Springer that centers on the ammo box. It's called Live 4 Box. He hopes to inspire other veterans to live for whatever they choose to keep in their box.